Patients with prostate cancer currently have access to a treatment alternative called prostate brachytherapy. This treatment alternative is performed as an outpatient procedure, has limited side effects and minimal interruption to daily living. Prostate brachytherapy combines transrectal ultrasound with radioactive seed implantation. Tiny radioactive seeds are permanently implanted directly into the middle of the cancer within the prostate gland during the prostate brachytherapy. The procedure is usually completed within 60-90 minutes. The cure rate of prostate brachytherapy compares favorably to surgery and external beam radiation therapy. More importantly, the side effects of brachytherapy seem to be more acceptable in that there is a very low risk of developing incontinence, impotence and rectal damage.
Using transrectal ultrasound, the prostate implant team determines the exact size of the prostate gland, the extent of the cancer and the amount of radioactivity required. This information determines the number of seeds needed and where they should be placed.
Typically, the patient arrives at the hospital two hours before the scheduled time of the procedure. The anesthesiologist determines the best type of anesthesia for the patient; generally a spinal anesthetic is administered so that the patient will have no feeling from the waist down.
After the anesthetic is administered, the prostate gland is located with transrectal ultrasound through a probe device shown in FIG. 1. The radioactive seeds are then placed within the prostate gland in a sequential fashion using needles inserted just behind the scrotum. Historically the needles are placed by hand, with template guidance. Ultrasound imaging, provides geometric feedback about the location of the needles, but does not provide the level of soft-tissue visualization of other imaging techniques. Dosimetric feedback is only available post-procedure, there is no option to adjust the implant dosage during the procedure based on dosimetric feedback. Thus, improvements in prostate brachytherapy are desired.